Dive Deeper Blog

NAS Sunscreen Study: From our Reef-safe and Human-safe Perspective

I was recently honored with an invitation to speak to a National Academy of Sciences subcommittee looking at the environmental impact of sunscreens. It’s a months-long investigation that brings people from the industry, dermatologists, and environmentalists together to consider the next steps toward protecting both people and ecosystems. 

Their first question focused on the efficacy of the various active ingredients – both chemical and mineral – and the application methods needed to protect human skin. 

On the surface, that’s an easy question because every formulation has to meet precise requirements set by the FDA before it is labeled as a sunscreen. The tests don’t look at ingredients at all, just how well they work in the very short term – does skin burn in 80 minutes? 

They totally avoided the hard answers though – are chemical sunscreen ingredients safe for people and aquatic environments – and that question has yet to be addressed by the people selling chemical sunscreen even though the FDA requested safety data from them in 2019. (Non-nano mineral sunscreens were specifically listed as safe and effective during that review process.)  

At the time, industry scientists said it wasn’t a pertinent question because sunscreen is applied to the skin and wasn’t absorbed to any significant degree. Wrong! Results published in the Journal of the American Medical Association showed that all the active ingredients tested were absorbed at levels that significantly exceeded the FDA’s threshold demanding further human toxicity testing. And not only were they absorbed into the body, they were detected in blood for weeks after application ended. 

To the best of my knowledge, there has been no formal industry response to very valid questions about human safety and absorption after just a single dose.  

Knowing that people use sunscreen to protect their skin from UV effects, it’s also important to understand how chemical sunscreens degrade when they’re exposed to UV light and chlorine in swimming pools. For instance, avobenzone breaks down unclassified and potentially toxic phenols in chlorinated swimming pools. And octocrylene, already suspected to be a reproductive toxin, degrades to benzophenone WITHIN sunscreen formulations in about 12 months. That means people are unwittingly applying a known carcinogen to their skin, including formulas labeled for children. 

And following that thought: if sunscreens are so effective, why are skin cancer rates skyrocketing while sunscreen sales also are increasing? There are a couple of important considerations: 

  • It could very well be the chemical ingredients in many of these sunscreens. They are clearly absorbed into the skin and bloodstream. Multiple reports from around the world have shown that oxybenzone damages reproductive systems; other chemicals and issues have not been well researched. 
  • Another potential cause: chemical sunscreens are absorbed into the skin where they act like a sponge, soaking up UV rays and releasing free radicals. While no definitive studies specifically link the free radicals created by chemical sunscreens to skin cancer, free radicals have been clearly linked to skin cancer. 
  • Or perhaps it’s that increasing levels of SPF doesn’t necessarily correlate with higher broad-spectrum protection?  An SPF 100 may prevent sunburn, but it can also allow sunbathers to absorb much higher levels of the UVA rays that cause long-term damage without any immediate discomfort from sunburn.  

Next week: what are the chemical properties of UV filters that may affect their fate in the environment. 

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I thank you for continuing to join us on this journey…because we DO have a choice and we can choose to do better. We appreciate your comments, concerns and questions that will help to ensure that we share information that is important to you along the way. 


Autumn Blum
Formulator & CEO

From Stream2Sea – Protect what you love 

Autumn is a cosmetic chemist and has been formulating natural and organic skincare for more than 20 years. Also an avid scuba diver, she founded Stream2Sea after seeing a sunscreen oil slick coming off a group of snorkelers.  Determined to make a difference, Stream2Sea is the only natural product line in the world tested and proven safe for freshwater fish, saltwater fish and coral larvae.                   

Stream2Sea is setting the standard for EcoConscious sunscreen and skincare. Along with standard human safety and SPF tests, Stream2Sea products are proven to be biodegradable in both salt water and fresh water, have passed a comprehensive series of aquatic toxicity tests and was formulated without ingredients known to harm the environment.  Formulated with powerful antioxidant blends to protect skin from sun damage, the Stream2Sea line includes sunscreens, conditioning shampoo and body wash, leave-in conditioner, nourishing body lotion and lip balms. Stream2Sea products are currently available online at www.Stream2Sea.com or ask for them at your favorite health food store, dive center or outdoor retailer. Friend us on Facebook or call (866) 960-9513. 


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